For the first time, scientists have sequenced the entire genome of the critically endangered Tasmanian spotted handfish, one of the world’s rarest fish.
The spotted handfish (Brachionichthys hirsutus) is named for its hand-like fins, which it uses to walk short distances on the shallow seabed. A relative of deep-sea anglerfish, the spotted handfish is an ambush predator with a lure that dangles near its mouth.
The Spotted Handfish – a fish as beloved as it is bizarre – scuttles along the sands on hand-like pectoral. Credit: © Rick Stuart-Smith
Found only in the waters around Tasmania’s south-east coast, the spotted handfish used to be plentiful until its population began rapidly declining in the 1980s. Scientists now estimate that fewer than 2,000 individuals remain.
Conservationists attribute the spotted handfish’s decline to a swathe of anthropogenic impacts including historical fishing practices, coastal development, pollution, climate change and invasive species.
Sequencing the genome promises to both illuminate the biology and ecology of the elusive spotted handfish and assist conservation efforts.
“The genome helps us understand how an organism functions,” says Gunjan Pandey, Senior Research Scientist at CSIRO, Australia’s national science agency. “It provides a foundation for understanding gene expression in daily life and offers insights into its evolutionary history.”
“With the genome, we can assist with species detection, monitor populations, and even estimate the fish’s lifespan,” says Pandey.
The opportunity to sequence the spotted handfish’s genome came when a captive individual died of natural causes.
“Marine species like the spotted handfish are notoriously difficult to work with,” says Pandey. “The DNA degrades rapidly and becomes contaminated with microorganisms. This makes assembling a pure genome extremely challenging.”